Question

Find the mean and variance for the data: | xi | 6 | 10 | 14 | 18 | 24 | 28 | 30 | |----|---|----|----|----|----|----|----| | fi | 2 | 4 | 7 | 12 | 8 | 4 | 3 |

Find the mean and variance for the following frequency distribution: | Classes | 0-30 | 30-60 | 60-90 | 90-120 | 120-150 | 150-180 | 180-210 | |---------|------|-------|-------|--------|---------|---------|---------- | | Frequencies | 2 | 3 | 5 | 10 | 3 | 5 | 2 |